They look excellent. I thought of doing a batch myself and selling a few off!
A surface grinder is a nice luxury to have and gives a very professional look and is obviously better than rubbing on a bit of emery cloth like I have to do for the port faces!
Got two questions...
What is the feature at the end of each cylinder? Is that cosmetic or just to further reduce the friction?
Also, why have you chosen to put the ports where they are instead of at the extreme ends of the cylinder? I have never thought of doing that before simply because of the more awkward angled hole. I can think of a few reasons for doing it now I've seen yours though. Have you done it to optomise the distance between the ports? (that was governed by the length of the piston rod and stroke on mine but your way gives more flexibility) Or was it so that your cylinder cover bolts don't interfere with the port? Are the covers going to be bolted? The only other reason I can think of is so that the port doesn't become uncovered by the cylinder when at 90 deg btdc like the mistake I made on mine! Or am I off the mark with these thoughts?
Thanks, you've given me some more ideas, although I want to tackle something more complicated than an oscillator next. I'm fed up of making those now but at least it was an inexpensive way to get back into the swing of things.